The present invention relates to novel aqueous preparations for the treatment of mineral building materials comprising (I) an aqueous emulsion of at least one polyfunctional carbosilane and/or carbosiloxane (A) and/or the (partial) condensation product thereof, (II) an emulsion of at least one organo(poly)siloxane (B), (III) at least one organic polymer (C) dispersible or emulsified in water, (IV) inorganic nanoparticles (D) dispersed or dispersible in water, and (V) optionally other additives (E).
The construction and building materials industry is searching for aqueous treatment agents for mineral building materials that impregnate or waterproof the materials well, that increase resistance to chemicals in order to protect against environmental influences, and that at the same time impart good easy to clean properties to the building material. In so doing, the appearance of the mineral building material must not be changed, for example, in order to protect monuments, natural stone facades, or terracotta materials from environmental influences or from graffiti.
Aqueous emulsions of organosilicon compounds have been successful as impregnating, waterproofing, and building protective agents for mineral building materials.
DE-A 19,517,346 describes, for example, aqueous emulsions of organosilicon compounds for waterproofing porous mineral building materials and building coatings. On mineral building materials, aqueous emulsions of organosilicon compounds produce only inadequate easy to clean properties.
DE-A 3,702,542 describes graft copolymers of (meth)acrylic acid derivatives and alkoxy-functional silicone resins for impregnation purposes, especially in buildings protection. Although those graft copolymers are good impregnating agents and, especially as a pigmented formulation, impart good easy to clean properties to mineral building materials, they contain organic solvents and change the visual appearance of the substrate.
WO 97/12,940 discloses aqueous preparations which comprise an emulsion of an alkoxysilane that is insoluble or only slightly soluble in water and a polymer containing alkoxysilane groups that is dispersible or emulsified in water.
In addition, coating compositions based on multifunctional carbosilanes are known, see U.S. Pat. Nos. 5,378,790, 5,621,038 and 5,686,523. The preparation of such hybrid materials is mostly carried out in dilute organic solution, generally by means of a sol/gel process, which is disadvantageous for many applications because, for example, with the known hybrid materials, a high molecular weight network is built up in a sol/gel process. Those high molecular weight polymers are not able to permeate the mineral building material very well and consequently result in a change in the surface of the mineral building material, which mostly becomes shiny. Moreover, relatively large amounts of solvent are necessary in sol/gel processes. That is undesirable because of the toxicological properties and the fire risk of the solvents, and existing VOC guidelines.
Accordingly, the object of the present invention was to provide an aqueous preparation that effectively impregnates or waterproofs mineral building materials, that imparts to the mineral building material adequate chemical resistance and good easy to clean properties, and that at the same time does not change the outward appearance of the mineral building material.
Surprisingly, it has now been found that that object is achieved by aqueous preparations that comprise an emulsion of at least one polyfunctional carbosilane and/or carbosiloxane (A), an emulsion of at least one organo(poly)siloxane (B), at least one organic polymer dispersed or emulsified in water (C), inorganic nanoparticles dispersed or dispersible in water (D), and optional other additives (E).